How Do I Override the Tab Page Shown After an Error in a List (Grid/Scroll)?
When an error is received (e.g. after a Save) it attempts to set focus on the relevant widget, which might require flipping to a different tab page. If the error relates to a list (grid or scroll) the system might not choose the tab page you'd prefer. In that event you can control the tab page that should be opened by defining the TabMenu function overrideErrorTabPage_​<LIST_​NAME>().
Example:

function overrideErrorTabPage_BPA() {
    return 'bussProcessAssistantStepPage';
}